Process of foaming resins using phosphorus-containing sulfonylhydrazides as blowing agents

ABSTRACT

THE INVENTION RELATES TO THE PROCESS OF INCORPORATING A PHOSPHORUS-CONTAINING SULFONYLHYDRAZIDE BLOWING AGENT INTO A RESIN AND HEATING THE ADMIXTURE TO FOAM THE RESIN.

Patented Jan. 12, 1971 Pa., a corporation of Pennsylvania v No Drawing. Original application Apr. 6, 1966, Ser. No. 540,486, now Patent No. 3,423,485. Divided and this application June 24, 1968, Ser. No. 753,818

Int. Cl. C08d 13/08; C08g 53/08; C08j 1/14 US. Cl. 260--2.5 4 Claims ABSTRACT OF THE DISCLOSURE The invention relates to the process of incorporating a phosphorus-containing sulfonylhydrazide blowing agent into a resin and heating the admixture to foam the resin.

This is a division of application Ser. No. 540,486, filed Apr. 6, 1966 now US. Pat. No. 3,423,485.

This invention relates broadly to a new class of blowing agents for resi-nous blends and more particularly relates to a new class of chlorosulfonated phosphorus-containing compounds useful as organic intermediates and to a new class of compounds particularly useful as blowing agents formed :by reaction of the organic intennediateswith hydrazine. The phosphoruscontaining blowing agents of this invention have the capability of imparting fire retardancy to the extent they are incorporated in resinous foams.

. The compounds of this invention are formed by initially chlorosulfonating pentavalent phosphorus esters to form compounds of the formula:

. These compounds are then reacted with hydrazine to form sulfonylhydrazides of the following formula:

In these formulas, R may be lower alkyl such as methyl and ethyl; R may be halogen, N lower alkyl, and -N; n is an integer from 1 to 3; n is an integer from 0 to 2; and the sum of m-l-n is not greater than 3, i.e. m+n is an integer froml to 3.

Representative of pentavalent phosphorus esters useful in the practice of this invention are the phosphates, phosphonates and phosphinates of the following formula:

The chlorosulfonated intermediatesare readily formed by. adding-the pentavalent phosphorus ester to excess chlorosulfonic acid, at least two timesthe amount of chlonited States Patent Ofice rosulfonic acid required for addition of each sulfonyl chloride group to the phenyl ring in accordance with the following equations:

No solvent is needed for carrying out the reaction and preferably the addition is carried out at a temperature of from about 20-25 C. with cooling if necessary. Upon completing the addition, the reaction mixture is heated at moderate temperatures, i.e. 50 C. or less, for at least 6 hours or until HCl evolution ceases.

The chlorosulfonated derivatives are then reacted 'with hydrazine by adding hydrazine to a solution of the chlorosulfonated phosphorus ester in a polar solvent such as tetrahydrofuran or acetonitrile. The addition is made with stirring at low temperature (0 to 10 C.) and, upon completion of the addition, the stirred solution is allowed to warm to room temperature. Usually 5% to 10% molar ex cess of hydrazine is employed, 2 moles of hydrazine per mole of sulfonyl chloride being required to complete the reaction:

The addition of hydrazine to the sulfonyl chloride as well as the low reaction temperature are employd to minimize the competing reaction:

EXAMPLE 1 Preparation of tris(p-chlorosulonylphenyl) phosphate hydrogen chloride was evolved. Upon completing the addition, the pale, clear, yellow reaction mixture was heated to 49 to 51 C. and maintained at this temperature range for 6 hours. The resultant clear, pale amber reaction mixture was carefully added dropwise to a suitable quantity of crushed ice (enough to maintain temperature of about 0-5 C.) A white solid precipitate was filtered and pressed dry; the clear, slightly yellow filtrate was discarded. Twenty-nine hundred (2,900) milliliters of chloroform was added to the powdered filtercake and a relatively small water layer containing a white semi-solid was separated from the lower, colorless, organic phase. After washing with three 25-ml. portion of chloroform, the aqueous layer which still contained a white gelatinous solid was discarded. The combined chloroform solutions was washed consecutively with two 50-ml.-portions of aqueous 10% sodium bicarbonate and three 100-ml. portions of saturated sodium chloride and dried over anhydrous magnesium sulphate. Concentration at reduced pressure (pot temperature of 4050 C.) of the dried chloroform layer to approximately 500 ml. gave a white solid slurry. The slurry was diluted with 500 ml. of hexane, cooled to and filtered. The washed and dried filter-cake (304.4 grams) softened at 103 C. and melted at 110118 C. Recrystallization of the reaction product from 3,000 ml. of a 3:1 carbon tetrachloride-benzene solution gave 265.3 grams of the chlorosulfonated triphenyl phosphate melting at 115- 119 C.

The recrystallized product was very soluble in chloroform, benzene, acetonitrile, dioxane, methyl ethyl ketone, methylene chloride and diglyme. Hexane and petroleum ether failed to dissolve the product, whereas some degree of solubility was achieved in hot cyclohexane and carbon tetrachloride.

AnaIysis.Calcd. for C H Cl O PS (percent): C, 34.77; H, 1.95; C], 17.11; P, 4.97; S, 15.47; mol. wt. 621.8.

Found (percent): C, 34.96; H, 1.96; Cl, 17.19; P, 4.99; S, 15.70; mol. wt. 593.3 as determined in THF by vapor pressure osmometry.

EXAMPLE 2 Preparation of tris(p-hydrazidosulfonylphenyl)phosphate Hydrazine (85%, 2.48 grams, 0.066 mole) was added dropwise in 10 minutes to a stirred solution of the chlorosulfonated triphenyl phosphate of Example 1 (6.21 grams, 0.01 mole) in 100 ml. of tetrahydrofuran at 4 C. Reaction temperatures were maintained at 5-l0 C. during the addition of hydrazine. After completing the addition, the reaction mixture was stirred and left to warm to room temperature over a period of 45 minutes. Tetrahydrofuran insolubles filtered and dried gave a slightly gummy white solid (2.5 grams). The tetrahydrofuran filtrate was washed with saturated sodium chloride, dried over magnesium sulphate, and then diluted with 250 ml. of cold petroleum ether. A white solid precipitated which, when filtered and dried, gave 4.6 grams of material melting at 144-147 C. (meq. of bromine required per gram: 18.7). Concentration of the tetrahydrofuran-petroleum ether filtrate left 0.7 gram of a solid, identified by melting point and mixture melting point as p-hydroxy benzene-sulfonylhydrazide.

The slightly gummy white solid obtained from the tetrahydrofuran insolubles was largely soluble in water. Its aqueous solution was combined with the saturated sodium chloride washings from the tetrahydrofuran layer. Treatmerit of the aqueous solution with excess concentrated sulfuric acid precipitated 3.3 grams of hydrazine sulphate, identified by melting point and mixture melting point.

The 4.6 grams of the crude white reaction product was dissolved in dimethylformamide (13 ml.) and precipitated by addition to 100 ml. of water. The filtered precipitate, washed with alcohol and water and dried, melted at 155157 C. with dec. One recrystallization from acetonitrile and absolute alcohol (3:5 mixture) gave material melting at 155.5-157 C. with dec. (after drying at 80 C. under an atmosphere of less than 1 mm.). The purified reaction product is very soluble in dimethylformamide, soluble in tetrahydrofuran or acetonitrile, and slightly soluble in hot ethyl alcohol. It is insoluble in water, ether, and hydrocarbon solvents.

Analysis.-Calcd. for C H N O PS (percent): C, 35.52; H, 3.48; N, 13.81; P, 5.09; S, 15.81; rneq. of bromine per gram=19.7.

Found (percent): C, 35.68; H, 3.60; N, 13.86; P, 5.11; S, 16.21; meq..of bromine per gram=19.2.

Thermal decomposition of tris(p-hydrazidosulfonylphenyl) phosphate Pure samples of. the reaction product from Example 2 e e ecom sed in a gas decomposition apparatus using Nujol (mineral oil) and dibutyl phthalate as diluents. The decompositions were carried out at several temperatures and the results, which appear in the following table, are reported in terms of ml. of gas (at S.T.P.) per gram of sulfonylhydrazide. Infrared spectra of gaseous reaction products failed to indicate any absorption; nitrogen evidently is the only volatile product. In addition, qualitative tests failed to indicate the presence of sulphur dioxide or hydrogen sulfide.

The gas yields were calculated based on the decompo sition reaction:

Based on this reaction the theoretical ml. of gas per gram of tris(p-hydrazidosulfonylphenyl) phosphate is 110.5 ml. (based on N evolved). In all cases, gas yields based on this decomposition reactions were in excess of TABLE I Ml. of

Degree gas per Hall-life,

temperature, gallon, Percent 1 C. at S.T.l. yield 1 minute Diluent 105 23 Dibutyl phthalate. I08 98 4 D0. 107 17 2 D0. 107 97 29 Nujol. .19 8 D0. 100 .10 3 D0.

1 Theoretical ml. per gram=110.5 (based on N: evolved).

EXAMPLE 3 Preparation of bis(p-chlorosulfonylphenyl) methylphosphonate Diphenyl methylphosphonate (63.3 grams, 0.26 mole) was reacted with 602 grams (5.16 moles) of chlorosulfonic acid in a manner similar to that described for triphenyl phosphate. Addition of the reaction mixture to ice, extraction with chloroform and concentration of the combined, washed and dried chloroform extracts followed by dilution of the concentrate (250 ml.) with pentane precipitated an oil. The solvent layer was decanted and the oil solidified on trituration with fresh ice cold pentane. The filtered, washed and dried white solid (78.3 grams) melted at 8186 C. A second crop of product (13.6 grams), melting point 8587.5 C., was obtained upon dilution of the chloroform-pentane filtrate with the nonsolvent pentane. The combined fractions of bis(pchlorosulfonylphenyl)methylphosphonate melted at 83- 86 C.

Recrystallization of the crude reaction product twice from a 50:50 benzene-ligroine mixture raised the MP. to 84.5 87 C.

Analysis.-Calcd. for C H Cl O PS (percent): C, 35.07; H, 2.49; C1, 15.92; P, 6.95; S, 14.40; mol. wt. 445.24.

Found (percent): C, 35.08; H, 2.60; CI, 15.82; P, 7.02; S, 14.45; mol. wt. 457.0 (determined cryoscopically in benzene).

EXAMPLE 4 Preparation of bis(p-hydrazidosulfonylphenyl) methylphosphonate To (bis(p chlorosulfonyl)phenyl methylphosphonatc (22.2 grams, 0.05 mole) dissolved in acetonitrile m1.) and maintained at 411 C. was added in 1% hours pink solid. This was dissolved in water (35 ml.) to give 6 EXAMPLES 6, 7, 8, 9 AND 10 1 4,4-oxybia (benzenesulfonylhydraside). 2 Tris (p-hydrazidosulfonylphenyl) phosphate. 3 Bis(p-hydrazidosulfonylphenyl) methylphosphonate.

a weakly basic solution. Neutralization of the aqueous solution followed by cooling failed to yield any solid. Addition of excess concentrated sulfuric acid, however, precipitated 13 grams (0.1 mole) of hydrazine sulfate identified by MP. and mixture M.P. The strongly acidic aqueous solution was discarded.

The combined acetonitrile filtrate and washings were concentrated to dryness at reduced pressure (pot temperature less 25 C.) and left a somewhat gummy white solid. The solid, washed with ether and dried in vacuo, weighed 22.75 grams and melted at 118-124 C. with decomposition. A filtered solution of the solid in dimethylformamide (30 ml.) added to water (700 ml.) gave an oil. On cooling and scratching the oil solidified. The resultant filtered white solid was washed consecutively with absolute alcohol and ether. The dried white solid weighed 17.35 grams and melted at 130-134 C. with decomposition.

-A portion of the reaction product was precipitated from its solution in dimethylformamide by addition to water and gave material melting at 132134 C. with decomposition after drying in vacuo l.0 mm.) at approximately 80 C.

Analysis.Calcd. for C13H1I7N4O7PS2 (percent): C, 35.78; H, 3.93; N, 12.84; 'P, 7.10; S, 14.70; meq, bromine per gram '18.4.

Found (percent): C, 35.84; H, 4.27; N, 12.91; P, 7.12; S, 14.84; meq. bromine per gram 19.0.

The following examples illustrate the utility of the phosphorus-containing sulfonyl hydrazides as blowing agents for resinous blend.

EXAMPLE 5 Free-flowing particles (dry blend) of plasticised thermoplastic vinyl resin were formed by mixing a masterbatch of the following composition in a Henschel Blender at a temperature below about 200 F.

Ingredient: Parts (grams) Polyvinyl chloride homopolymer having a number ave. mol. wt. of 26,000 and a wt. ave. of 54,000 (determined by gel. permeation chromatography) 1,000 Dioctyl phthalate 700 Epoxidized soybean oil 50 Liquid Ca-Ia octaoate stabilizer 40 50 mesh limestone 100 TiO pigment Calcium silicate 7.5

The sheet formed in accordance with Example 6 was well fused throughout and flexible. It had a density of about 72.8 pounds per cubic foot. The sheet formed in accordance with Example 7, using a commercial blowing agent, was a flexible fine celled foam having a density of about 35.9 pounds per cubic foot. Both sheets formed in accordance with Examples 8 and 9 were flexible fine celled foams having densities of 38.7 and 30.1 pounds per cubic foot, respectively, although the sheet of EX- ample 9 had a slightly coarser cell structure. The sheet of Example 10 was a flexible fine celled foam having a density of 38.1 pounds per cubic foot.

The preferred percentage range for blowing agent is between about 1.0% to 5.0% by weight, based on the organic resin component.

We claim:

1. The process which comprises incorporating a phosphorus-containing sulfonylhydrazide of the formula:

wherein R is lower alkyl,

R is a member selected from the group consisting of halogen, N0 lower alkyl, and H,

m is an integer from 1 to 3,

n is an integer from 0 to 2, and

n-l-n is an integer from 1 to 3,

4. The process in accordance with claim 1 in which the sulfonylhydrazide is of the formula:

i Beams-Q-m-r o References Cited UNITED STATES PATENTS 2,830,086 4/ 1958 Stempel, Jr. 260-2.5 3,423,485 l/ 1969 Herewh et al. 260-923 MUR-RAY TILLMAN, Primary Examiner FOELAK, Assistant Examiner U.S. Cl. XJR.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 55%93 Dated January 12, 1971 John E. Herweh and Algirdas C. Poshkus Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, the first formula should appear as follows:

( flii iS-(mm) G g R 1 Column 1, line 48, "and N" should read --a.nd H--; line &9, the firs letter "n" should be --m--. Column 2, after'H SO" in last equation,

add a subscript line 28, insert the word "a' before "5% to line the word "employd" should read --employed--; in first line of Example 1 "(p-chlorosulonylphenyl)" should read --(p-chlorosulfonylphenyn Column h, line 21, "reactions" should read --reaction--; Table I should appear as follows:

TABLE I Dec. Ml. of gas Yield Half-life Diluent Temp. C. per g. at S.T.P. 1: min.

136 95 23 Dibutyl phthalat 2 II II 13 107 97 29 Nujol Theoretical ml. per gram 110.5 (based on N evolved).

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,55%93 Dated January 12, 1971 John E. Herweh and Algirdas C. Poshkus Page 2 Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column line 65, "(bis(p chlorosulfonyl) phenyl" should appear as --bis(p-chlorosulfonylphenyl)--. Column 5, line k0, should read --per I 18.h.--; line b2, should read --s, 1h.8 meq. bromine per gram 19. line +5, "blend" should read --blends--; line +8, "plasticised should read --plasticized--; line 60, "Ca-Ia" should appear as --Ca-Zn--. Col Table II should appear as follows:

Table II Masterbatch Blowing Agent Temp. Upper Temp. Lower g rams) (grams) Platen Platen Time Ex. 6 300 o 1o2o F. h2o F. 1 min. Ex. 7 296.5 3.5 (1) 1o2o F. +2o F. 1 min.1 Ex. 8 296.5 3.5 (2) 1012 F. +2o F. 1 min.I Ex. 9 295 5 (2) 1022 F. +2o F. 1 min, Ex. 10 296 h (3) 1015 F. 20 F. 1 min.

4,h'-oxybis (benzenesulfonylhydrazide) Tris(p-hydrazidosulfonyl'phenyl) phosphate Bis(p-hydrazidosulfonylphenyl) methylphosphonate Claim 1, the subscript "2" should read as subscript --m--; the subscrip1 should read as subscript --n--; line "n n is an integer" should re --m n is an integer--.

Signed and sealed this 21st day of December 1971.

(SEAL) Attest:

EDWARD M.FIETCHER, JR. ROBERT GOTTSCHALK Attesting Officer Acting Commissioner of Patent 

